#include  <cstdio>
#include  <iostream>
using namespace std;

int main(int argc, char *argv[])
{
	char a[100][20];
	int n,m,sum,line;
	char c;
	while(scanf("%d",&n) && n != 0)
	{
		getchar();
		sum = 0;
		int i = 0, j =0;
		while(true)
		{
			c = getchar();
			if(c == '\n')
				break;
			a[i][j] = c;
			//cout << i << j << c << endl;
			if(i%2 == 0)
			{
				j++;
				if( j == n)
				{
					j--;
					i++;
				}
			}
			else
			{
				j--;
				if( j == -1)
				{
					j++;
					i++;
				}
			}
			sum++;
		}
		m = sum / n;
		for( int i = 0; i < n ; ++i )
			for( int j = 0 ; j < m ; ++j )
				printf("%c",a[j][i]);
		printf("\n");	
	}
}
